A. Technical Field
The present invention relates generally to contacts for electrically connecting a substrate and a semiconductor device mounted to the substrate. More particularly, the present invention pertains to the bump contacts that are employed in the flip-chip packaging of semiconductor devices to electrically couple contact pads on a semiconductor device with a substrate to which the semiconductor device is mounted.
B. Background of the Invention
Bump contacts streamline the packaging of semiconductor devices by eliminating the use of electrical leads to connect each of the numerous contact pads on a semiconductor device to corresponding conductors on a support substrate to which the semiconductor device is mounted. Neither the gossamer quality of such electrical leads, nor the substantial number required in order to effect necessary electrically communications for even a single semiconductor device, are optimally suited to efficient industrial manufacturing processes.
Furthermore, a bump contact between a contact pad on a semiconductor device and a conductor on a support substrate reduces dramatically the electrical distance between the contact pad and the conductor relative to that attainable using an electrical lead. In contrast with such electrical leads, a bump contact has only a single end at which attachment is required, and attachments effected through bump contacts are considerably more mechanically robust than the attachments that arise at either end of an electrical lead.